|LV= County Championship Division Two, Chelmsford (close, day one)|
|Essex 279: Mickelburgh 50, ten Doeschate 48, Hogan 4-36|
|Glamorgan 40-3: Rudolph 17no, Ryder 3-18|
|Essex lead by 239 runs|
|Essex 3 pts, Glamorgan 3 pts|
Glamorgan maintained the form that has put them firmly in the promotion picture by bowling out Essex for 279 on the opening day at Chelmsford.
Pace bowler Michael Hogan led the way with 4-36 for the Welsh county, who have won four of their last five games.
Jaik Mickleburgh made 50 and eight other batsmen reached double figures without any playing a major innings.
Glamorgan, however, struggled to 40-3 at stumps in reply as all-rounder Jesse Ryder picked up 3-18.
|Will odds favour Essex again?|
|Essex have not lost a home game in which they have won the toss since May 2012 - five wins and five draws since then|
They began the game in third place, 20 points behind Surrey, but with a game in hand, and seized the upper hand after Mickleburgh and Tom Westley, who was bowled by Hogan, departed in the space of four deliveries.
Ryan ten Doeschate made 48 and Graham Napier hit 42 off 27 balls for Essex, who are fifth in the table, with a 58-point gap to make up on Surrey.
They were all out in the 79th over, but with 15 to survive before the close, Glamorgan soon had Will Bragg caught behind and Ryder then won lbw decisions against teenager Aneurin Donald and Andrew Salter in successive overs as Essex ended a difficult day in positive fashion.
Glamorgan bowler Michael Hogan told BBC Radio Wales Sport:
"It would have been nice if we didn't lose any wickets tonight.
"We bowled quite well as a group on what we thought was a pretty flat wicket.
"It's good that we bowled them out, but it was not an ideal start with the bat."